This is a prospective study of the health consequences of glucose intolerance. Two groups of subjects expected to have highly contrasting rates for cardiovascular disease on the basis of virtual obliteration of the female sex advantage with the development of diabetes mellitus will be studied. The subjects are a group of 685 women with a predefined abnormality of the three hour, 100 gram oral glucose tolerance test (OGTT) and 328 randomly selected negative (i.e., normal OGTT) controls. Initially tests were performed with the natural metabolic stress provided by pregnancy and abnormal tests reverted to normal following delivery. Annual testing followed for most of the intervening years in a longitudinal study that is showing a 17 to 22 year development of diabetes mellitus in less than 5 percent of the controls, and over 40 percent in those initially abnormal with the remainder revealing all grades of evolving diabetes. The unusual opportunity of investigating etiologic clues for cardiovascular complications provided by these contrasting groups that cover the whole spectrum of emerging diabetes will be enhanced by the racial mixture of the study with its 30 percent black component. Current uncertainties concerning the relationship between glucose intolerance and diabetes, on one hand, and its vascular complications, on the other, will be amenable for study. Response variables will include blood pressures, graded exercise electrocardiograms, peripheral vascular disease by segmental blood pressures using Doppler ultrasonic flow detectors following exercise, peripheral pulse wave contours, pulse rate response to postural change, and a standardized history for angina pectoris, TIAs, intermittent claudication and myocardial infarction. Examination will document congestive heart failure, renal, cerebral and fundoscopic abnormalities. Blood studies will include OGTTs, cholesterol, triglyceride and HDL with detailed quality control procedures. Lipoprotein phenotyping and identification of secondary hyperlipoproteinemics will be included.